On Saturday 16 October 2004 12:44 am, William Chops Westfield wrote:
> On Oct 15, 2004, at 5:55 PM, steve@tla.co.nz wrote:
> > The statement "if(3==foo)" is written in the opposite way to how you
> > would describe what the statement is doing, so the statement isn't
> > immediately and inherently self documenting.
>
> I dunno.  It's just not ENGLISH.  Mathematicians will consider
> an equality statement fully reversable; "foo = 3" is precisely
> identical to "3 = foo"; one of the foundations of algebra, sort of.

To add to the arguement....    :-)
If you look at the output of some compilers, you may find disagreement too.

if (foo == 3) {

would collect "foo" and subtract the #3 to test for zero

if (3 == foo) {

would collect 3, place it on the stack, then collect foo, then subtract foo 
from stack value "3"

it doesn't seem to sound like much, but if you have seen a DWORD being done 
on a 16bit compiler, you do see a fair bit of juggling of values.

To me, if (foo == 3) is just more "efficient" from a compiler point of view.
likewise, I would also prefer to see complicated stuff on the left with 
simple stuff on the right... therefore, preference for:

if (foo == 3) {
if (function(foo) == 3) {
if (function(foo1) == foo2) {
if (function1(function2(foo1) == function3(foo2))

also in the name of efficiency, it makes sense to test for something more 
likely, then test for something less likely, so:

(poor example, but hopefully conveys the idea)
if ((c < 32) || (c == EOF)) {   <- more likely to encounter c < 32

would be prefered versus:

if ((c == EOF) || (c < 32)) {  <- only going to encounter EOF only once
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